Pressure relief device for swimming pools

ABSTRACT

Pressure relief assembly for a swimming pool that presents a smooth surface to the upper surface of the bottom of the pool when the valve is in a closed position.

BACKGROUND OF THE INVENTION

It is known that in-ground swimming pools are built with pressure relief plugs placed at strategic locations in the bottom of the pool. The pressure relief plugs can either be spring activated or mechanically removed when the swimming pool is emptied of water. The pressure relief devices are required so that water pressure building up underneath an empty swimming pool can be forced into the pool and thus removed conveniently. It has been known on several occasions, where there have been no spring activated water pressure relief devices or the mechanical pressure relief devices have not been removed, when the pool is empty and left unattended, that significant water pressure build up underneath the pool has caused the pool to lift out of the ground. After the pool has lifted out of the ground, it is very difficult to get it to go back to its original location. Point of fact, most of the time the swimming pool has to be destroyed and a new pool put in its place.

The construction of concrete pools with pressure relief devices is state of the art. However, the current spring loaded pressure relief valves are so entrusted that, when installed, they project above the bottom surface of the pool.

BRIEF DESCRIPTION OF THE INVENTION

The present invention pertains to a device to contain a spring loaded pressure relief valve in the bottom of a swimming pool so that the pressure relief device does not protrude above the surface of the pool thus, making a smooth service on the bottom of the pool, one that will not catch debris or interfere with the feet of a swimmer or other person using the pool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of a swimming pool containing a pressure relief device according to the prior art.

FIG. 2 is a section taken along line 2-2 of FIG. 1.

FIG. 3 is a cross-sectional view of an apparatus according to the present invention.

FIG. 4 is a cross-sectional view of an apparatus according to the present invention in association with a spring loaded pressure relief valve.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a swimming pool 10 having a sloping bottom 12 is generally filled to a level shown by line 13. Conventional in-ground swimming pools made of poured or gunned concrete generally have a shallow end 14 and a deep end 16. In a conventional concrete pool the deep end 16 bottom contains a conventional water return fixture 17 for collecting pool water for recirculation through a water filtration system. Likewise, the shallow end 14 also contains an identical water return fixture 17′. Water return fixtures 17, 17′ are fitted with safety covers 18, 18′ as is well known in pool construction and user safety. The bottoms of fixtures 18,18′ are generally fitted with plugs (not shown) that can be removed when the pool is empty periodically for cleaning or painting. Removal of the plugs allows water accumulating under the pool to enter the pool for removal, thus preventing water pressure from building up under the pool.

In addition to pressure relief plugs in fixtures 18,18′ additional pressure relief devices such as represented by box 19 are installed in the bottom of a pool. One type of device comprises a threaded hollow internally threaded cylindrical receptacle and a threaded cap or plug to close the pressure relief passage defined by the hollow passage extending through the bottom 12 of pool 10. The conventional receptacle positions the plug in generally flush with the bottom 12 of pool 10.

Another type of pressure relief device such as shown at 20 in FIG. 1 can include a spring loaded pressure relief device which is also placed into the bottom of the pool. A portion of pressure relief device 20 projects above the bottom 12 of pool 10 into the swimming area where it can be a tripping hazard and collection point for debris entering the pool.

As shown in FIG. 2, the pressure relief device 20 includes a collar 22 which is fixed to a generally hollow receptacle 24 which projects through the bottom 12 of the pool 10 into a layer of stone 21. The layer of stone 21 is used to accumulate and drain water away from the bottom of the pool. Device 20 includes a spring loaded valve closure element 26, shown in a raised position, which fits inside a valve body 28, such device as being well known in the construction of concrete swimming pools.

In the event that a swimming pool is empty and an excessive amount of water builds up in the stone layer 21, the valve closure element 26 can be raised by the water pressure and the water will be caused to flow into the bottom 12 of the pool 10 where it can be conveniently evacuated by an auxiliary pump. As stated above, it is well known that if a pool is emptied and excessive water pressure is not relieved the pool can be lifted clear out of the ground.

The major drawback with the device 20 is that it projects above the floor of the pool 12.

Referring to FIG. 4 of the present invention, in combined form is a stepped cylindrical device 30 which has a first or upper portion of larger diameter 32 and a reduced or lower portion of a smaller diameter 34 in combination with a pressure relief device 20. The upper portion 32 is generally of a smooth wall construction and can be fabricated from well known pool materials such as plastic or stainless steel. The lower section 34 can be a continuation of upper section 32 or can be a separate structure bonded to the upper section. The lower section 34 contains internal threads 36 which are adapted to receive conventional pressure relief devices such as a spring loaded pressure relief device 20 shown in FIG. 2.

The size of the device is such that the upper portion 32 is of a sufficient length to enclose the pressure relief device 20 when it is inserted into the threaded portion 34 of device 30 and that the upper lip 38 of device 30 can be incorporated into the bottom of the pool 12 in a flush position so that when the pressure relief device 20 is inserted into device 30 and the pressure relief device 20 is in a normal closed position maintained by spring 44, the top of the valve closure element 26 of pressure relief device 20 is flush with the upper surface 38 of portion 32 of receiver 30 and in turn flush with the inner surface of the bottom of a pool.

The pressure relief device 20 in the closed position, being flush with the top edge of 38 of device 30, prevents any part of device 20 from coming in contact with the foot of a swimmer or pool user and prevents accumulation of debris against the device 20.

The bottom portion 34 of device 30 is sized so that it will project through the bottom of the pool into the stone layer 21 as shown in FIG. 2. The diameter of portion 34 of device 30 has an internal dimension so that projections 40,42 on device 20 just clear the internal diameter of device 30. Thus, when the pressure relief valve is inserted into device 30, which has previously been incorporated into the bottom of the swimming pool, the pressure relief device 20 presents a continuous or flat surface to the bottom of the pool thus minimizing or eliminating any debris that can gather around the pressure relief device 20 and furthermore, the device of the present invention prevents a swimmer or a user of the pool from tripping or contacting the pressure relief valve when it is in a closed position. 

Having thus described my invention what is desired to be secured by Letters Patent of the United States is set forth in the appended claims.
 1. A pressure relief apparatus for incorporation into the bottom of a swimming pool comprising: a receiver having a generally stepped cylindrical cross-section with a large diameter portion of said receiver adapted to be incorporated into the bottom of said swimming pool with an upper surface of said large diameter positioned flush with the an upper surface of the bottom of said pool adjacent water in said pool; and a smaller diameter portion of said receiver containing internal threads being of sufficient length to project through said bottom of said pool into a water accumulation structure underneath said pool.
 2. An apparatus according to claim 1 including a pressure activated relief valve incorporated into said large diameter portion of said receiver, said pressure activated relief valve so constructed and arranged to be contained within and flush with said upper surface of said receiver when said valve is in a closed position.
 3. An apparatus according to claim 1 wherein said device is fabricated as a single construction from a pool water compatible material.
 4. An apparatus according to claim 2 where said relief valve is a spring loaded pressure activated device. 